Condenser



Feb. 8, 1927. 1,616,832

R. C. SPRGUE CONDENSER Filed Sept. 18. 1925 Ifatented Feb. 8, 1927.-V

' iiasszf TED Sp'fTAToE-S PATEN-T' 1 '(I-FFICE' BOBEETQ SPRAGE, OF QUINGY, MASsAoHUsE'r'rs;

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Application filedV September 18, 192 5. Serial No. 57,110.

' 'S' i fr-My present invention relates: to condensers, 'andmoreparticularly tio animproved condensenof vvariable capacity. v7111.1variable condensens as: heretofor-e con-' ,sthucted; itis customaryl to utilizefiplates of 'flf'metal'ssuch plates-being. arrangedil in groups V51''seriesiandieach'group'or series movable Vnot, however, as far as i io 'cilbidisplacement and relatively large A capacity ;byl

'-relatively to'anothengroupor series. It has If am aware, been 'possible'to construct'a'condenser of small uti-lizin'gv metal. plates as? the rmaturesfig'ain; 'heretoforezfit 'has not been: considered- 'possible rtox .manufactu're a ;condenser'of the i Variabl'e typew'ithz tin' foil the 'armature' material; r

2 :z In :mfy presentv inventionz'I have: obviated theobjectionable features of prior devices of this characten land'havfe produced a' conden= sen' Orthevariable' tpe, utilizing tin foil as the* anmatures ztliereof andy which condenser,

whilevariable and of relatiivelr large' capacity, 4is!offrelati'vely smallvcubicdisplaoement. 'Ehel principalfi ,object VVof my invention, therefore,lisan improved. oondenser; fnother object of my invention is anim- .pnoivedl cond'ens'er of'th'e izariable` type: 'A funther object of'm invention is an'v im'- fprovle variablefcondenser:utilizing tinfoil the: armaa'ures.` i In' the' axccompa'nying drawings illustrating thaprefen'ed embodiment 'of my' invention,

I vfcoifelenser; z

is? an enlarged 'sectional Vside elevaftidn! taken on the'lne/2-2'of Fig. 1

Fi'gf'fis a?'prsp `'e1ctivev view of a portion v 'of' the conrenserstructure showing the manranizedjf '11,

front| elevati'onv of an ven'closmg -caselinwhich the condenser structure shown f fin Eigsllu2gand`3-may-be=placed, and fur- 'fto 'Fig.7 is 'asectional side? elevati'on on the V zime 1;? ofrig; e, a

,*Rett'erringto the dra'wings, and particularlyto'Fi'g's. 1`and'2, itwill be noted' that the erjne'lfiseri is'rnade 'up ofA alternate layers of and'a. thinr'she'etv metali, as tiin foil.

' the elements 10,

ing'utilized in a manner' There is shown a layervof paper 10, then a layer of thin sheet metalv 11, as foil, then ar second layer of paper 12', and finallfy alayor of thin sheetmetal 1'3,fas.foil. liachy layer. lland 12 of paper. or other suitable dielectric is preferably made up of twosheets and each layervlO is continuous fronrone end of the condenser to the other, as indicated in Fg. 1-. '1`he layers sandj 12.7V are of' suitable width and are also ofV any suitablelength, the. length depending', of course, on the ca,- pac'it-y of the condenser' it isldesired Zto construct. Between Jthe| layers 10 andl'2 of paper is placed the layer 11, 'preferably of tin foil,,although any othersuitable-material may be employed. tinuousilength and? the length is: such that it is slightly shorter than Vthe overall length ofthe'layers 10 and 12, and also thewidth thereof is l'ess than the width'of the layers 10 and 12, all as clearly indicated in Fi. 1 where such layer 11 is shown by the dotted lines. Connected to the layer 11 and extendinglaterally` outward' therefrom is a strip' 14 ofcopper or other suitable material and whichA is used as a connectingx strip for connecting the plate 11 in a circuit.. Resting'on'thetop layer 12 of paper* is a layer 13 of tin foil, this Vlayerbeing madeupof a plurality of sectionsl'a, 13, 13, 18, etc., the Sections being arrangedV end' to end withfa spaee'between them. This plate 13 formcd of the' sectionslffl, 13.V 13, and 13, vforms the second' plateor armature' of the' condenser. To each of the'sections 13, 18, 13, and 18 is connected a 'thi-n strip of sheet material 15,

15, 15, and ldrespectiafely, these lstrips being formed' preferably of spring copper' or springaphosphorl bronz'e.4 These strips eX- tendf latera'lly outwa'rdfrom the Sections 13,

tion of' such strlpsv will heherei'nafter described; Tov assemble the' condzenser, a block 16 of insulating' material and of1 suitable length and width is utilized and on which finished condenser having` the Shape or form shown in per'spe'ctive' in'Fig. Referrrng to this Fig-' 8, it will' be' not/ed that the connecting strips 15, 15, 15,`and 15I are of Varying leng'ths,

to be hereinafter described.

The condenser structure 'shown in Fig. 3 is pref-erably mounted in a bo-X vor case 17 of This layer is onecone 131, 13and 13d respectively, and the disposif- 11, 12, VandV 13' are roll-ed, the f 'this difference' inlength beinsulating material, a bracket 18 being utilbrought into ized to hold the condenser structure in position adjacent to the bottom of the box.

VVhen thus positioned, and referring to Fig. 6, it will be noted that vthe ends of the connecting strips 15, 15h, 15, and 15d lie the terminal 19 iselectrically connected the terminal plate 14 atta-ched vto the condenser plate or armature 11. The terminals 19 and 20 are provided With thumb screws 21 and 22 respectively, and by means of which terminal wires, as those indicate'd by the numerals 23 and 24 respectively may be connected. Secured to the terminal 20 is a terminal plate 25 which extends inwardly on top of the condenser structure Within the box and forms a spring contact plate fora purpose to be hereinafter described. Also securedto the contact 20 and extending along the bottom of the box 17 is a'contact plate or strip'26 which is connected to a Vterminal 27 at the other end of the box 17. Secured to the contact 19, to which is attached the contact strip 14, is a contact plate or strip 28, this contact strip or plate passing along he bottom Vof the box 17 and being connected to a terminal 29 at the'other end of such box. Fitting on the top of the box and secured thereto in any suitable manner, as by screws 30, is a cover plate 31, this cover plate being provided with perforations through which may pass thumb screws 21l and 22 leading to the terminals 19 and 20 respectively. Centrally located on the cover` plate 31 so as to be rotatable therein is'ashaft 32 threaded at its outer end to receive a knurled thumb nut 33 and having secured to its inner` end a circular plate 34 of insulating material. Secured to the inner face of the plate 34 in any suitable manner, as ,by screws is a semi-cireular plate 36 of condueting material such, for example, as copper. This plate 36 is adapted to engage with the inwardly extending ends 'of the connecting strips 15, 15, 15, and 15, it being apparent that one or any number of the connectingl strips may be in engagement with the disc 36 or that none of such connecting strips may be in engagement therewith.Vv Further. the dise 36 is in electrical engagement with the shaft 32 and as the end of this shaft 32 engages with the conducting plate 25, it is obvious that either of the connecting strips 15, 15, 15, and 15, or any or all of them may be i electrical connection with the strip 25, and therefore with any conductingr element. as 24, that may be connected to the terminal 20. The shaft 32 is rotatablc in either direc'tion, and such shaft has atta che thereto above the cover plate 31 a hand or pointer 38 that may be brought intopregistry Awith any one of a pluralityof indicating points 39 formed in the base of the cover plate 31.

- By making the length of the Sections 13a, 13, 13, and 13l different from each other, it is obvious that the surface area of each of the said sections Will bc difl'ercnt and The capacity ;of the condenser could' be furthe'r increased by adding sections 13 and 13d in succession. The abllity to do this is rendered possible by rotating the shaft 32 to the right, as indicated in Figs'. 4 and 6, thus bringing the disc 36 into engagement With the'contact plates 15, 15, 15, and 15'l in succession, thus placing a variable capacity across 'the terminals 19 and 20, also the terminals 27 and 29. This arrangement has the additional advantage that a possibility of seven variations can be' obtained with only the four Sections 13, 13, 13, and 13l shownthus. If we assume' that the lengths of the Sections 13, that each senarately with the plate 11 has a. capacity of 7, 6, 6, and 4 respectively, then it is obvious that, if the shaft 32 is turned vto the left, as viewed in Figs. 4 and 6, we

`zet successive capacities of 4, 10. 16 and 23 while. if the shaft is turned to the right, as viewed in Figs. 4 and 6, we will get capacities of 7, 13, 19, and 23. Therefore it is 'possible toobtain seven different capacities: 4, 7, 10,13, 16, 19, and 23, obtained vwith only four sections, this being accomplished by giving the Sections the proper, lengths in relation to each other. The above is merely a--typical-example as any desired combination of capacities may be obtained by properly proportioning the area of the sections 13", 13, 13, and 13.

VVhile I have necessarily shown and do' scribed the preferred embodiment ofimy invention somewhat in detail, it is to be underi' stood that I may vary the size, Shape, and arrangement of parts within wide Iimits without departing from the spirit of the invention.

I claim as new is: o

1. Animproved condenser comprising' a pair of armatures` one of said armatures being composed of a plurality of sections of Havine; thus described my invenfion, What ,25

'various lengths arranged end to end and 13", 13, and 13a is such' eleetrically insulated from each other, and 13 *meansfor' bringing;y said Sections into elec- 10 Vsaid Sections, a rotatably mounted wiper associated with said contact arms, and means for rotating said wiper in either direction about its axis whereby a plurality of combinations of electricalvalue for the contrical engagement with each other in any desired. order.v

2. An improved lcondenser comprising a 5 air of armatures,

denser are obtained greater thanl the numher of Sections empioye In testimony whereof, I have signed my name to this specification.

ROBERT C. SPR-AGUE;

one of said arinatnres he- Vmg V.cornposed of va' plurality of Sections o Vvarious lengths placed'end to end and arranged in series `and electric-Ally insuiated fromzeach other, a.v contact arm for each o 

